The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 1981
Filed:
Nov. 29, 1979
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Disclosed is a biaxially stretched, composite polypropylene film suitable for use as an electrical insulating film, comprising a first layer comprising a first propylene polymer and having a maximum roughness height R.sub.z of its exposed surface of about 0.5 .mu.m, and a second layer contiguous to the first layer comprising a second propylene polymer having a composition different from the first propylene polymer and having a roughness height R.sub.z on its exposed surface ranging between about 0.2 .mu.m and 0.4 .mu.m, with the composite film having a modulus of elasticity of at least about 2000 N/mm.sup.2 in all directions of the plane of the film and a DC dielectric strength of at least about 650 V/.mu.m. Also disclosed is a capacitor comprised of a plurality of these composite films having a metal surface layer and being laminated with one another.